Variation in Definition of Homicide

Mallory O'Brien, Harvard University

Eileen Weller, Milwaukee Co. Medical Examiner's Office

Jeffery Jentzen, Milwaukee Co. Medical Examiner's Office

ABSTRACT

Objective: Compare manner of death as certified by medical examiner (ME) on death certificate to district attorney (DA) charging decision and final disposition of case in court system in an effort to identify the frequency of and factors contributing to a disparity in classification of homicide by MEs and prosecutors. Methods: Cases certified by county ME to be homicide, accidental motor vehicle deaths and accidental firearm deaths from 1990 through 1999 were matched to cases presented to homicide unit of DA's office from October 1991 through 1999. Results: Of 1247 cases certified as homicide by ME, 766 were matched to DA homicide cases. Factors influencing successful matching included apprehension of perpetrator(s) and prosecution in adult court. In a sample of 67 homicide cases reviewed but not charged by DA's office, 47% determined to be self-defense, 26% insufficient evidence, 11% no defendant or death of the defendant, 3% accidental shooting, and 13% other. Conclusions: There is variation in how medical and legal practitioners define "homicide." This variation results from different goals of practitioners, as expressed in levels of intentionality and differing burdens of proof (reasonable medical certainty vs. beyond a reasonable doubt). Effects of such variation have yet to be determined.